/*
* Copyright 2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: Messages.java,v 1.4 2004/12/16 19:21:44 minchau Exp $
*/
package org.apache.xml.serializer.utils;
import java.util.ListResourceBundle;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
/**
* A utility class for issuing error messages.
*
* A user of this class normally would create a singleton
* instance of this class, passing the name
* of the message class on the constructor. For example:
* <CODE>
* static Messages x = new Messages("org.package.MyMessages");
* </CODE>
* Later the message is typically generated this way if there are no
* substitution arguments:
* <CODE>
* String msg = x.createMessage(org.package.MyMessages.KEY_ONE, null);
* </CODE>
* If there are arguments substitutions then something like this:
* <CODE>
* String filename = ...;
* String directory = ...;
* String msg = x.createMessage(org.package.MyMessages.KEY_TWO,
* new Object[] {filename, directory) );
* </CODE>
*
* The constructor of an instance of this class must be given
* the class name of a class that extends java.util.ListResourceBundle
* ("org.package.MyMessages" in the example above).
* The name should not have any language suffix
* which will be added automatically by this utility class.
*
* The message class ("org.package.MyMessages")
* must define the abstract method getContents() that is
* declared in its base class, for example:
* <CODE>
* public Object[][] getContents() {return contents;}
* </CODE>
*
* It is suggested that the message class expose its
* message keys like this:
* <CODE>
* public static final String KEY_ONE = "KEY1";
* public static final String KEY_TWO = "KEY2";
* . . .
* </CODE>
* and used through their names (KEY_ONE ...) rather than
* their values ("KEY1" ...).
*
* The field contents (returned by getContents()
* should be initialized something like this:
* <CODE>
* public static final Object[][] contents = {
* { KEY_ONE, "Something has gone wrong!" },
* { KEY_TWO, "The file ''{0}'' does not exist in directory ''{1}''." },
* . . .
* { KEY_N, "Message N" } }
* </CODE>
*
* Where that section of code with the KEY to Message mappings
* (where the message classes 'contents' field is initialized)
* can have the Message strings translated in an alternate language
* in a errorResourceClass with a language suffix.
*
* More sophisticated use of this class would be to pass null
* when contructing it, but then call loadResourceBundle()
* before creating any messages.
*
* This class is not a public API, it is only public because it is
* used in org.apache.xml.serializer.
*
* @xsl.usage internal
*/
public final class Messages
{
/** The local object to use. */
private final Locale m_locale = Locale.getDefault();
/** The language specific resource object for messages. */
private ListResourceBundle m_resourceBundle;
/** The class name of the error message string table with no language suffix. */
private String m_resourceBundleName;
/**
* Constructor.
* @param resourceBundle the class name of the ListResourceBundle
* that the instance of this class is associated with and will use when
* creating messages.
* The class name is without a language suffix. If the value passed
* is null then loadResourceBundle(errorResourceClass) needs to be called
* explicitly before any messages are created.
*
* @xsl.usage internal
*/
Messages(String resourceBundle)
{
m_resourceBundleName = resourceBundle;
}
/*
* Set the Locale object to use. If this method is not called the
* default locale is used. This method needs to be called before
* loadResourceBundle().
*
* @param locale non-null reference to Locale object.
* @xsl.usage internal
*/
// public void setLocale(Locale locale)
// {
// m_locale = locale;
// }
/**
* Get the Locale object that is being used.
*
* @return non-null reference to Locale object.
* @xsl.usage internal
*/
private Locale getLocale()
{
return m_locale;
}
/**
* Get the ListResourceBundle being used by this Messages instance which was
* previously set by a call to loadResourceBundle(className)
* @xsl.usage internal
*/
private ListResourceBundle getResourceBundle()
{
return m_resourceBundle;
}
/**
* Creates a message from the specified key and replacement
* arguments, localized to the given locale.
*
* @param msgKey The key for the message text.
* @param args The arguments to be used as replacement text
* in the message created.
*
* @return The formatted message string.
* @xsl.usage internal
*/
public final String createMessage(String msgKey, Object args[])
{
if (m_resourceBundle == null)
m_resourceBundle = loadResourceBundle(m_resourceBundleName);
if (m_resourceBundle != null)
{
return createMsg(m_resourceBundle, msgKey, args);
}
else
return "Could not load the resource bundles: "+ m_resourceBundleName;
}
/**
* Creates a message from the specified key and replacement
* arguments, localized to the given locale.
*
* @param errorCode The key for the message text.
*
* @param fResourceBundle The resource bundle to use.
* @param msgKey The message key to use.
* @param args The arguments to be used as replacement text
* in the message created.
*
* @return The formatted message string.
* @xsl.usage internal
*/
private final String createMsg(
ListResourceBundle fResourceBundle,
String msgKey,
Object args[]) //throws Exception
{
String fmsg = null;
boolean throwex = false;
String msg = null;
if (msgKey != null)
msg = fResourceBundle.getString(msgKey);
else
msgKey = "";
if (msg == null)
{
throwex = true;
/* The message is not in the bundle . . . this is bad,
* so try to get the message that the message is not in the bundle
*/
try
{
msg =
java.text.MessageFormat.format(
MsgKey.BAD_MSGKEY,
new Object[] { msgKey, m_resourceBundleName });
}
catch (Exception e)
{
/* even the message that the message is not in the bundle is
* not there ... this is really bad
*/
msg =
"The message key '"
+ msgKey
+ "' is not in the message class '"
+ m_resourceBundleName+"'";
}
}
else if (args != null)
{
try
{
// Do this to keep format from crying.
// This is better than making a bunch of conditional
// code all over the place.
int n = args.length;
for (int i = 0; i < n; i++)
{
if (null == args[i])
args[i] = "";
}
fmsg = java.text.MessageFormat.format(msg, args);
// if we get past the line above we have create the message ... hurray!
}
catch (Exception e)
{
throwex = true;
try
{
// Get the message that the format failed.
fmsg =
java.text.MessageFormat.format(
MsgKey.BAD_MSGFORMAT,
new Object[] { msgKey, m_resourceBundleName });
fmsg += " " + msg;
}
catch (Exception formatfailed)
{
// We couldn't even get the message that the format of
// the message failed ... so fall back to English.
fmsg =
"The format of message '"
+ msgKey
+ "' in message class '"
+ m_resourceBundleName
+ "' failed.";
}
}
}
else
fmsg = msg;
if (throwex)
{
throw new RuntimeException(fmsg);
}
return fmsg;
}
/**
* Return a named ResourceBundle for a particular locale. This method mimics the behavior
* of ResourceBundle.getBundle().
*
* @param className the name of the class that implements ListResourceBundle,
* without language suffix.
* @return the ResourceBundle
* @throws MissingResourceException
* @xsl.usage internal
*/
private ListResourceBundle loadResourceBundle(String resourceBundle)
throws MissingResourceException
{
m_resourceBundleName = resourceBundle;
Locale locale = getLocale();
ListResourceBundle lrb;
try
{
ResourceBundle rb =
ResourceBundle.getBundle(m_resourceBundleName, locale);
lrb = (ListResourceBundle) rb;
}
catch (MissingResourceException e)
{
try // try to fall back to en_US if we can't load
{
// Since we can't find the localized property file,
// fall back to en_US.
lrb =
(ListResourceBundle) ResourceBundle.getBundle(
m_resourceBundleName,
new Locale("en", "US"));
}
catch (MissingResourceException e2)
{
// Now we are really in trouble.
// very bad, definitely very bad...not going to get very far
throw new MissingResourceException(
"Could not load any resource bundles." + m_resourceBundleName,
m_resourceBundleName,
"");
}
}
m_resourceBundle = lrb;
return lrb;
}
/**
* Return the resource file suffic for the indicated locale
* For most locales, this will be based the language code. However
* for Chinese, we do distinguish between Taiwan and PRC
*
* @param locale the locale
* @return an String suffix which can be appended to a resource name
* @xsl.usage internal
*/
private static String getResourceSuffix(Locale locale)
{
String suffix = "_" + locale.getLanguage();
String country = locale.getCountry();
if (country.equals("TW"))
suffix += "_" + country;
return suffix;
}
}